Preparation of layered Li（Ni1/3Co1/3Mn1/3）O2 as positive material for lithium-ion secondary battery

The uniform layered Li（Ni1/3Co1/3Mn1/3）O2 cathode material for lithium-ion secondary batteries were synthesized by using （Ni1/3Col/3Mn1/3）（OH）2 synthesized by a liquid phase co-precipitated method as precursors and with NiSO4, COSO4, MnSO4 and NH3·H20 as raw materials. The influence of the preparation conditions such as precursors preparation, calcinations temperature and calcinations time on the structural and electrochemical properties of the Li（Ni1/3Co1/3Mn1/3）O2 were systematicelly studied. The result of XRD shows the 1003//104 value of the Li（Ni1/3Co1/3Mn1/3）O2 powder synthesized at 950 ℃ for 10 h is 1.26, which illustrates the well-ordered layer-structure. The average particle size of uniform Li（Ni1/3Co1/3Mn1/3）O2 powder is about 400 nm in diameter as observed by scanning electron microscopy, The first discharge capacity of Li（Ni1/3Co1/3Mn1/3）02 electrode is 174.6 mA.h/g at 16 mA/g between 2.8 V and 4.5 V versus Li at room temperature, and the capacity retention is 95.2% of the initial discharge capacity after 50 cycles at 32 mA/g.